Lessons from LIGO

At the end of a very exciting week I had the pleasure last night of toasting LIGO and the future of gravitational wave astronomy with champagne at the RAS Club in London. Two members of the LIGO collaboration were there, Alberto Vecchio and Mike Cruise (both from Birmingham); Alberto had delivered a very nice talk earlier in the day summarising the LIGO discovery while Mike made a short speech at the club.

This morning I found this interesting video produced by California Institute of Technology (CalTech) which discusses the history of the LIGO experiment:

It has taken over 40 years of determination and hard work to get this far. You can see pictures of some of the protagonists from Thursday’s press conference, such as Kip Thorne, when they were much younger. I bet there were times during the past four decades when they must have doubted that they would ever get there, but they kept the faith and now can enjoy the well-deserved celebrations. They certainly will all be glad they stuck with gravitational waves now, and all must be mighty proud!

Mike Cruise made two points in his speech that I think are worth repeating here. One is that we think of the LIGO discovery is a triumph of physics. It is that, of course. But the LIGO consortium of over a thousand people comprises not only physicists, but also various kinds of engineers, designers, technicians and software specialists. Moreover the membership of LIGO is international. It’s wonderful that people from all over the world can join forces, blend their skils and expertise, and achieve something remarkable. There’s a lesson right there for those who would seek to lead us into small-minded isolationism.

The other point was that the LIGO discovery provides a powerful testament for university research. LIGO was a high-risk experiment that took decades to yield a result. It’s impossible to imagine any commercial company undertaking such an endeavour, so this could only have happened in an institution (or, more correctly, a network of institutions) committed to “blue skies” science. This is research done for its own sake, not to create a short-term profit but to enrich our understanding of the Universe. Asking profound questions and trying to answer them is one of the things that makes us human. It’s a pity we are so obsessed with wealth and property that we need to be reminded of this, but clearly we do.

The current system of Research Assessment in the UK requires university research to generate “impact” outside the world of academia in a relatively short timescale. That pressure is completely at odds with experiments like LIGO. Who would start a physics experiment now that would take 40 years to deliver? I’ve said it time and time again to my bosses at the University of Sussex that if you’re serious about supporting physics you have to play a long game because it requires substantial initial investment and generates results only very slowly. I worry what future lies in store for physics if the fixation on market-driven research continues much longer.

Finally, I couldn’t resist making a comment about another modern fixation – bibliometrics. The LIGO discovery paper in Physical Review Letters has 1,004 authors. By any standard this is an extraordinarily significant article, but because it has over a thousand authors it stands to be entirely excluded by the Times Higher when they compile the next World University Rankings. Whatever the science community or the general public thinks about the discovery of gravitational waves, the bean-counters deem it worthless. We need to take a stand against this sort of nonsense.

Incidently, the NZ Herald also have a video of Roy Kerr’s reaction to the news, which is the best ever vindication of the Kerr solution:http://www.nzherald.co.nz/world/news/article.cfm?c_id=2&objectid=11588700
I think this should be compulsory viewing for those who looked made that viral video of Andrei Linde being told about the premature release of BICEP2 results that eventually bit the dust.

Incidently, since there has been so much discussion about Nobel prizes in these columns, a few comments are in order. Firstly I agree totally that this year’s prize has to go to LIGO. This is a community effort; it’s theirs. But in addition as a sociological comment, I note that theoretical general relativity has always been a bit too far ahead of the game in terms of the community of those nominating for the Nobel prize.

Einstein himself received the prize in 1921 for “services to theoretical physics and especially … the photoelectric effect”. Relativity was still just a bit too radical then despite Eddington’s measurement of the bending of light. Chandrasekhar had to wait 50 years to get the prize for predicting white dwarfs. Why? Because Eddington dismissed it on account of his own prejudices, and the astrophysicists of the day who did not want their Newtonian models challenged were happy to seize on the support of one well-known expert.

As for black holes, since every astrophysical body in the universe rotates, in spite of the Schwarzschild solution the prevailing view was that if you added rotation then the problematic horizon and singularities would go away. That was until the Kerr solution was found in 1963, and the golden age of relativity began. Ironically, the first 1963 Texas symposium was called because the buzz was all about the newly discovered quasars. What eventually turned out to be the central engines of quasars – supermassive black holes with accretion disks and jets – was presented at that meeting in a 10 minute talk by Kerr which the audience paid little attention to. The word black hole was only coined in 1967 by Wheeler (reportedly borrowed from someone who asked a question at a public lecture). In their first few decades black holes still seemed a bit too radical, but over the years astronomers slowly changed from using the words “black hole candidates” to “black holes” without quite realizing when the transition occured.

So now LIGO detectors have accurately measured the collision of two black holes initially with small (or antiparallel) spins merging into a single black hole with spin 2/3 of the maximum predicted by the Kerr solution. Fittingly, the ringdown is based on the quasinormal mode analysis techniques pioneered among others by Chandrasekhar, who said “In my entire scientific life, extending over forty-five years, the most shattering experience has been the realization that an exact solution of Einstein’s equations of general relativity, discovered by the New Zealand mathematician, Roy Kerr, provides the absolutely exact representation of untold numbers of massive black holes that populate the universe.” LIGO’s discovery was possible because these objects exist, and people like Roy and Chandra predicted what to see.

Anyway, the Royal Swedish Academy have finally recognized Roy Kerr. They have a lesser known (but almost equally valuable) prize – the Crafoord Prize in Astronomy – which will be presented to Roy Kerr and Roger Blanford in May. The prize – for the supermassive black hole processes which are already well observed for decades – was announced last month. It will be a great party, even more so on account of the LIGO result!

He didn’t coin it. (You qualify your statement somewhat, but repeat “coined…by Wheeler”.) Popularized it? Certainly. But then Pat Boone popularized rock ‘n’ roll. 🙂 There was a talk on this at the 50th-anniversary Texas Symposium (in Dallas, where the first one was, and Wolfgang Rindler was still there and in good spirits and even drove Rocky Kolb to the public talk). Almost all of the old guard of GR people were there: Kerr, Misner, Newman, Rindler, DeWitt-Morette, Penrose. Check out this great video of the panel discussion:

You can even see my balding head in the audience. Newman’s story about Norway was worth the cost of travelling to the conference. Watch his hole contribution, though, or indeed the entire discussion. (Interestingly, Wolfgang Rindler had told me the same story (but, of course, with Newman as the protagonist) a couple of days before, but if I say why that would give away the punch line.)

Oh, and Blandford, and Weinberg, and Ellis, and Ruffini, and Schücking via video message (too ill to travel, as was Maarten Schmidt).

I’ve been to several Texas Symposia, which I find to be among the best conferences. They are always in December, which usually means winter, but not in 2017 in South Africa (which should be much cheaper than last year’s in Geneva, even including the travel).

David. Thank you for the link to Roy Kerr’s interview. Very inspiring and refreshing as you mention. Does anyone know of reactions from Joe Taylor or Russell Hulse to this discovery? After al it was their discovery of 1913B+16 which put an end to all doubts regarding theoretical issues about whether GW’s carry energy or not (which was something very strongly debated earlier)
Also I don’t think alternatives to Kerr BH are completely ruled out yet from this detection.
David : Recently Mike Nauenberger has pointed out that Stoner
had discovered Chandrasekhar limit before him and should have got much more credit than he gets.

“Does anyone know of reactions from Joe Taylor or Russell Hulse to this discovery? After al it was their discovery of 1913B+16 which put an end to all doubts regarding theoretical issues about whether GW’s carry energy or not (which was something very strongly debated earlier)”

What should their reaction be and why would it be interesting?

Of course, Taylor was in Dallas as well, along with many of the usual younger suspects.

Reblogged this on Disturbing the Universe and commented:
Lots of good stuff here including the fact I noted on Thursday that the KIGO papers, despite being a huge advance, will be deemed worthless by THES.

“Sworn to secrecy until recently, he had deliberately titled the talk ‘100 Years of Relativity – Where are the Waves’ so that, on the day of the talk, he just crossed out the W!”

Good move. When I was working in Groningen, I heard a talk at the internal seminar on “The nature of high-velocity clouds”. By the time I heard it, the corresponding paper had been accepted in Nature, so the title was changed to “High-velocity clouds in Nature”. 🙂